DESCRIPTION: The overall goal of this project is to construct recombinant filamentous bacteriophages to be directly used as reagents in diagnostic hemagglutination assays. The M13 phage will be engineered to express antibody to a conserved cell surface marker on human erythrocytes (GFA) and a peptide from HIV-1. When these recombinant phage are placed in direct contact with a blood sample from an HIV-1- infected individual, erythrocyte agglutination will be induced by anti- antigen antibodies present in the serum, that will bridge the phage particles attached to different red blood cells. In phase 1, a M13 phage expressing anti-GFA antibody and HIV peptide will be constructed, and a assay will be developed using known antibodies and sera from HIV-1 infected individuals. In phase II, the sensitivity and specificity of the assay will be determined. Successful demonstration of this method will provide a rapid, inexpensive assay for HIV and other infectious diseases. PROPOSED COMMERCIAL APPLICATION: Proposed commercial application not available.